Method of making cushion solid tires



Nov. 27, 1928.l 1,693,409

L.. N. SOUTHMAYD METHOD OF MAKING CUSHION SOLID TIRES md April 18. 1923 C 2 :295' )Wd/0% y O' I ATTORNEY.

Patented Nov. 27, 192s.-

UNIT-ED s TATEsf Il 1,693,409, PATENT A OFFICE.

LEON N. s oUTHMAYD, or SPRINGFIELD, MAs'sAcHUs'ETfrs, AssrGNoR 'ro THE FI'sx RUBBER COMPANY, or cHIcorEE FAL-Ls, MAssAcHUsETTsg'in CORPORATION or MASSACHUSETTS. i

METHOD'OF WIAKIITGPv CUSHION SOLID TIRES.

'appncationmea Aprii 1s, 1923. seria; No. 632,510.

This invention relates to methodsv of mak-'I tire, whereby the'internal recess will be lo- Ycated in the finished tire with great accuracy. It has for a fu-rther object an improved cushion tire and rim combined in an integral.- unit. It has various other and further'objects which will appear from the following description and claim.

.The 'invention will now be described in. the accompanying drawings,4

connection with in which f Fig. 1 is a section showing one stage. in the building of a tire having asingle cin cumferential recess;

Fig. 2 is a section of the completed tire;

Fig. 3 is a detail section of a securing de-A vice for the annular core;

method ofpreparing the tire, .the tire being also shown in this case with two recesses instead of one; and

after completion..A

Oneproposed form ofcushion solid rubber tire has a circumferential internal -cavity or recess to permit iexing of the rubber; thus increasing the easy riding qualitiesof the vvrigid core forthisl purpose has necessitated the splitting of the rim so that *the core can be removed after vulcanization. This weakens the rim, or requires extra. expense in later welding v or otherwise joining lthe rim sections. By the method of' my invention the necessityv for splitting the rim is done away with, while at the -same timethe adf vantages of incompressibility inherent in the rigid core are retained. l

Throughout the gures the tire has been shown in radial section without any attempt being made to'show it in full circumference, this manner of representation being common in similar cases. The tire is shown as mounted on an annular metal rim 10, having side flanges 11' and dovetails or other roughening 12 to increase the adhesion between the rim and the tire. It is customary in the Fig. 4 is a section showing a 'modified'.

tire and prolonging itslife. '-The yuse of a building of solid tires to have a `layer of -hard rubber next to the rim in 'order tor 'make more `perfect thebonding at this point.

The hard rubber is shown at 13. Either directly upon this hard rubber orupon a slight thickness of superposed soft `.rubber similar to 'the body ofthe tire, is placed an annular bag'14ofrubber or rubberized fabric, and. shaped to; correspond to the recess 'desired in the completed tire. The bfagis rovided rwith a valve 15, whereby it may e filled with water and sealed up. Thel valve con-` veniently passes through the rim so that the waterfcan be drained out'after vulcanization.

In case difficulty is experienced in preservingfthe'bag atA the exact center of the tire throughout thev circumference, it canbe held -in place by lugs illustratedl in Fig. 3, their use being preferred as a means of insuringy proper registration' of the. bag. AA convenient form ofvlug is shown lin Fig.A 3. It comprises a grommet or ferrule 16 embedded in the body-of the bag, and a screw .17 passgrommet. y f After the bag is located the tire is built up around it'e1ther b y laminating strips of rubber or extending amass of rubber of the Fig. 5 is a section of the tire of Fig. 4

proper form. The built up tire is inserted in the lusual vulcanizing mold (which in .this

recess), and subjectedl to heat and pressure to vulcanize the rubber@ The tube o'r bag 14 is filled with 'water either under 'a constant pressure maintained through the valve ing through the ri'm andfthreaded into'the or with the valveclosed so that'the water causes the bagto act as an incompressible' core. After vulcanization the valve may be opened, and the water allowed to escape.

g A modification of the' building process is illustrated in..Fig. 4, which,is of use in cases where it is diiiicult to Akeep the bags in position due to the fiow of rubber duringmolding or some other cause. In this case the tire is partially built up (Fig. 4) around anannul-ar metal core 18 (shown as two lin number in Fig. 4 to produce a tire with two recesses like Fig.. 5). vThese metal cores have necks 19 by which. theyfcan beheld centered during thev building operation. The tire so built around lthe cores is given a 'partial'vulcanization inra suitable mold, one form of which is shown in Fig. 4. In

the illustrated case it comprises a tread ring 20, a base .ring 21, and side members 22.A

The tread ring has grooves for the necks 19 of the cores, so that they are positively held against movement during'J molding. After this partial vuleanization the rubber `0 the tire Will have sus suiciently to premainderof the ,tire can nowbe built up over the bags, suitable allowance being made in theoomposltion of the stocks for the necessary difference 1n cures, and vulcanization completed as in the case of the tire built up around the bag as first described. Y

around a rigid core having an external projection preventing closing of the tire material-around the core, partially vulcanizing the tire,V removing the core, inserting a liquid-containing bag, completing the building of the tire, and completing the Vulcanizatioh ,of the tire While said bag is filled With liquidrunder pressure.

LEON N. SOUTHMAYD. 

